The present invention is directed to a reciprocating piston pump more specifically to a reciprocating pump having a piston comprised of a spherical segment reciprocating within a flexible cylinder.
The use of a piston in a reciprocating piston pump wherein the piston is a segment of a sphere is old and well known as evidenced by the U.S. Pat. Nos. 2,710,137 and 3,716,310. Such a configuration enables the piston to be in engagement With the chamber Wall of the cylinder even in the most tilted positions of the pitman relevant to the cylinder axis. The cylinders in both of these patents are constructed of a hard rigid material Guenther teaches the use of an annular ring of soft pliable material about the convex parameter of the piston but does not provide any means for adjusting the diameter of the annular ring to accommodate wear.
The U.S. Pat. No. 4,449,446 is directed to a ballistically tolerant control system for a cylinder-piston assembly wherein the piston is controllably positioned within the cylinder which is provided with a deformable sleeve so that when the cylinder is deformed by sharp impact the piston can still continue to reciprocate within the cylinder due the the deformation, either due to frangibility or softness, of the sleeve.
In the construction of prior art pumps it is old and well known as evidenced by the U.S. Pat. No. 1,610,174 to locate the cylinder between a pair of opposed heads which are interconnected by a plurality of tension rods located externally of the cylinder about the circumference thereof. Thus, the rigid cylinder is clamped between the opposed heads.